Acidyl dialkylrhodamin and process of making same.



-UNITED STATES PATENT OFFICE.

CARL HOFFMANN, OF HOCHST-ON-THE-MAIN, QERMANY, ASSIGNOR TO FARE- WERKE, VORM. MEISTER, LUOIUS & BRUNING, OF HOCHST- ON- THE- MAIN, GERMANY, A CORPORATION OF GERMANY.

ACIDYL DIALKYLRHODAMIN AND PROCESS OF MAKING SAME.

SPECIFICATION forming part of Letters Patent No. 694,149, dated February 25, 1902. Application filed December 10, 1901. Serial No. 85,309- (Specimens) To aZZ whom it may concern:

Be it known that LCARL HOFFMANN, Ph. D., a citizen of the Empire of Austria-Hungary, residing at Hochst-on-the-Main, in the Empire of Germany, have invented certain new and useful Improvements in the Manufacture of Rhodamin'Derivatives, of which the following is a specification.

I have found that acidyl derivatives of metar0 amidophenol, such as acetyl-meta-amidophenol (meta -oxyacetanilid) or benzoyl-metaamidophenol, (meta-oxybenzanilid,) may be condensed with dialkylamidooxybenzoylbenzoic acid and that acidulated asymmetric dialkylrhodamins are thus obtained. These dyestuffs are substances of metallic luster, and when pulverized dark-red powders soluble with diliiculty in water and dilute mineral acids and insoluble in ether, but readily diszo solved by hot alcohol, the solutions having an eosin or pink-red color and fluorescence. They dye mordanted calico bright yellow-red to bluish-red shades. By separating the acid radical from the new dyestuffs the asymmet- 2 5 ric dialkylrhodamius are obtained. As condensation agent it is best to use concentrated sulfuric acid. The following example illustrates the process:

Example: Four parts, by weight, of diethyl- 3o amidooxybenzoylbenzoic acid are dissolved in forty parts of concentrated sulfuric acid of 66 Baum specific gravity. To this mixture are added at to centigrade, while stirring,two parts of meta-oxyacetanilid. When 3 5 all has dissolved, the whole is allowed to stand for four to five hours. The mixture is at first yellow, but soon becomes dark and then brown red, having finally a distinct fluorescence. The mixture is then poured on ice 0 while stirring, and the product of condensation separates as a crystalline mass. Washed with water and dried the product is a darkred powder soluble with difiicultyin water and dilute mineral acid, insoluble in ether. It is, however, easily dissolved by hot alcohol. The dilute alcoholic solution is pink red and has a green yellow fluorescence. When heated with dilute mineral acid, it is transformed into asymmetric dialkylrhodamin.

The procedure is similar when other acidylmeta-amidophenols and other dialkylamido oxybenzoylbenzoic acids are used. The corresponding products are analogous to the compounds having the general properties already described above.

Having now described my invention, what I claim is- 1. The herein described process for the manufacture of acidulated asymmetric dialkylrhodamins which consists in condensing dialkylamidooxybenzoylbenzoic acids with acidyl-meta-amidophenols, substantially as set forth.

2. As new products, the acidulated asymmetric dialkylrhodamins, being substances of metallic luster and when pulverized red powders, soluble with difficulty in water and dilute cold acid, insoluble in ether, but readily dissolved by hot alcohol, the alcoholic solutions are pink red and dye mordanted calico bright yellow-red to bluish-red shades; said products when heated with dilute mineral acid are easily transformed into the asym metric dialkylrhodamins.

3. The hereindescribed process for the manufacture of acidulated dialkylrhodamins, which consists in condensing diethylamidooxybenzoylbenzoic acid with meta-oxyacetanilid, substantially as set forth.

4:. As a new product, the acidulated asymmetric diethylrhodamin, being in a dry state a dark-red powder, soluble with difficulty in water and dilute acid, insoluble in other, but readily dissolved by hot alcohol, the dilute alcoholic solution is pink red and has a greenyellow fluoresence; it dyes mordanted calico bright yellow-red shades and when heated with dilute mineral acid is readily transformed into asymmetric .diethylrhodamin.

In testimony that I claim the foregoing as my invention I have signed my name in presence of two subscribing witnesses.

CARL HOFFMANN.

Witnesses:

ALFRED BRISBOIS, JOHANN HARTENSTEIN. 

